Synthesis and Structural Characterization of a Novel Layered Lithium Manganese Oxide, Li0.36Mn0.91O2, and Its Lithiated Derivative, Li1.09Mn0.91O2

A novel layered lithium manganese oxide, Li0.36Mn0.91O2, has been prepared from Li2MnO3 by acid digestion. The structure of the product consists of alternate layers of trigonal prisms, partially occupied by Li+ ions, and edge-shared octahedra, occupied almost completely by Mn4+ ions. Lithiation of this product with Lil at 80°C forms a rock-salt phase, Li1.09Mn0.91O2, in which the cubic close-packed oxygen array of the parent Li2MnO3 structure is regenerated.